Tranny rebiulders-727 test plate.

[torredcuda]

After having to pull my freshly rebiult trans for what we hope is just a nicked or rolled sealing ring we want to bench test everything we can before reinstalling it.My manual shows a test plate to air test some things and we found out they want $180+ for one!It`s just a flat plate with some holes and I could make one at work if I had the dimensions for it.Any of you tranny guys have one you could measure up for me or even better borrow and I could bring it into work and use a scan machine to pull the dimensions off of.I would gladly pay shipping both ways to be able to borrow one.Or do I even need one?Can I just blow the air directly into the ports?

[tactransman]

No you do not need one.Just blow directly into the ports. I will get a pic to you tomorrow when I get to the shop. What was your trans. doing wrong?

[torredcuda]

First and second worked fine but it didn`t want to go into third and was slow going into reverse until I reved it up.Book diagnosis was bad sealing ring for high/reverse clutch.

[tactransman]

So do you have it all apart now?

[torredcuda]

Yup,just replaced all the sealing rings but it`s not assembled yet,probably assmble in the next couple nights.

[tactransman]

You need to set the drum on the pump and air check it, before you put it in the case.

[tactransman]

Here is a pic.
Plus application chart if you do not have one.

[ShelbyDogg]

Torredcuda,

When you rebuilt your trans, did you pull the piston out of the Front drum and change the inner and outer sealing rings? Having a cracked rubber piston seal on the front drum would cause the problem that you described. When putting the piston back in, use tranny fluid and a feeler guage to work the seal in, without tearing it.

Rob

[torredcuda]

Rob we did but must have nicked it even though we coated them with fluid and used the feeler gage to work them in.We`ll air check everything this time to make sure it`s working OK.
Tac,you say to set the drum on the pump and air check it,can I do that on the bench and where exactly do I blow the air into?

[tactransman]

With the drum off of the pump, blow air into the hole between the two large outer sealing rings. Where that air comes out is where you will blow air into with the drum placed back on the pump.Try alittle bit of air, it should not take much to make the clutch pack apply.

[torredcuda]

Just tried it and everything seems to be working good,didn`t take much air pressure to apply the clutch pack.

[ShelbyDogg]

So, what was the original problem with the trans? Are you using the same valve body or did you change it out?  When you put the piston rubber rings on the front drum, are you sure that the lips are facing the correct direction? When you rebuilt it, did you change the brass bushings to tighten up the clearances?  There are too many variables not answered here.   Was this the first tranny that you have done?

Rob

[tactransman]

Was there any hard parts changed (pump,drum etc.)
What brand/kind of valve body do you have?

[torredcuda]

To give you the history on the trans it was purchased 8-9 years ago from Fairbanks for my `72.It was their street/strip full manual reverse valve body.I also got a TCI 11" street fighter converter that stalls around 2800-3000 rpm.That first trans lasted all of about 1 mile,it was a quick test spin down the road and back but by the time I pulled into the driveway it was slipping so bad we had to push it back into the garage.After much hassle I got another one to replace it and that one would flare between 1-2 and 2-3 shifts.More hassle and finally got a third one which shifter hard 1-2 but still had a little flare 2-3 under hard acceleration.The first two supposedly were a bad batch of pumps that developed cracks,the third I just lived with for a couple years and then went and converted to a four speed.Before I put it the 69 my friend(has some experience biulding race powerglides) and I went thru and rebiult it with new clutches,bands etc.All parts were checked and clearances set and installed,no hard parts changed.

[tactransman]

It sounds like maybe a mismatch/bad  parts maybe from Fairbanks.